The present invention relates to heat exchangers especially to those used as a condenser in a refrigeration system.
A conventional heat exchanger has a plurality of tubes, a pair of header tanks and joint pipes on the header tanks. In such a heat exchanger, one end of the joint pipe is inserted into an opening of the header tank and is brazed temporarily. After that, the joint pipes, the header tanks and tubes are brazed together in a furnace.
In other conventional heat exchangers, after brazing the tubes to the header tanks, the joint pipes are brazed to the header tanks. Since it is more difficult to maintain a relative position between the joint pipes and the header tanks than between the tubes and the header tanks during a brazing operation, the brazing of the header tanks and the joint pipes is carried out independently.
Japanese laid opened utility model publication Nos. 1-151087 and 1-151088 show a heat exchanger which has a joint block to which a joint pipe is inserted and brazed. The joint block has a concave surface on which the header tank is brazed. The joint pipe is kept stable in the brazing operation by such a construction.
As described above, it is necessary to braze the joint pipe independently or else the joint block is required to keep the joint pipe stable during the brazing operation, thus requiring additional steps of processing and a high cost is incurred.
In the conventional heat exchanger, the joint pipe projects out from the outline of the heat exchanger, which reduces the amount of space available for mounting other parts in an engine room.